Internal-combustion engine



0er. 9, 192s. l1,687,348

`H. H. PLATT INTERNAL COMBUSTION ENGINE Filed Feb. 20, 1925 2 Sheets-Sheet 2 gg z.

Patented Oct. 9, 1928.

UNIT Eo STA@ HAVILAND H. rLAT'r, or WALLINGFORD, mi;NsYLvAN1A. f fiNrERNAL-CMBUSTION ENGINE.

nppiication inea February 20,19%.vr yseran No. 10,5473. y

My invention .relates to internal combustion engines, Yand more particularly to that Y type of engine in which a charge-of-fuel is compressed kand transferred to a combustion engine of the above noted type whiclishall be capable of delivering greater power ywith a smaller consumption of fuel than hitherto has been att-ained in enginesof similar displacements. Y -v t A further object is to provide an engine more compact and lighter in weight than engines of the saine rating heretofore constructed. f

Another object of the invention is to pro,-` vide an engine which shall be comparatively cheap to construct and to maintain.

A further object ofthe invention is to provide an engine in which the 'number-of parts is reduced to a minimum and in whichtliese parts areso arranged that they shall notbe subject to disorders nor require .frequent in spection and repair. A. y

A still further `object of the invention is to provide an engine incapable of .backiring The invention further contemplates the provision of a novel method for'operating an engine of the above stated type. .n .v r These objects and other advantageous ends I secure as hereinafter set forth,reference being had to the accompanying drawings, lin,

which: y v

Figure 1 is a longitudinal'verticalsection on the line a-a, Fig. 3;

Fig. 2 is a transverse verticalsection on the v line b-?), Fig. 3; and

Fig. 3 is a horizontal ce-c, Fig. 1. v l.

With reference to the drawings, my engine may comprise the usual crank case 1 provided sect-ion von the line The crank shaftmay carry the usual wheel (not shown),and has inthe interio-r of the casing 1 a vcrank 5. The shaft 4-v also carries in the interior of the casing 1. an ec'- centric 6 provided with a strap 7S to which is attached a forkedeccentric rod 8.V

My engine further comprises a casting 9 which, as shown in Fig. 1, contains cylinder a cylinder whose upper portion 10 is of lesser diameter than the lower portion 1l., and within this cylinder isa piston having upperand lower portions 12 and 13 of different diameters adapted respectively to operate in the said upper and lower portions of the cylin- .l

der. The piston 12-13 is operatively connected with thecrank 5 of the shaft 4 through Athe usual connecting rod 14. The cylinder and piston preferably arek so proportioned that t-he area of the upperv end of the piston is somewhat greater than the effective area of the lower enlarged portion 13.r

The cylinder 10--11 is provided with three ports; one15,at the topof the'upper smaller section 10 of the cylinder; another, 16, also in the smaller section 1() but intermediatethe top and bottom thereof, and a third, 17, at the top of thecylinder section r11 of greater diameter. Collapsingfspring packing rings 18 bearing inwardly against the piston are set in anannular recess at the bottom' yof the section 10 of the cylinder, and are retained by a segmental follower ring 19, -as clearly illus-y trated; and each ofthe sections'12 and 13 of` the piston. is provided withtheusual piston rings20.

In addition to the cylinder 10-11, the cast# infr 9'comprises'avcylinder 21, which preferably parallels the said cylinder lil-11, and

like the latter has its longitudinal axis in a plane'with the axis of the shaft 4. The cylinder 21, as sho-wn in Fig.1, communicates with the cylinder-104411v through the ports 15 and 17, and has also an intake port 22, near t-he lbottoni thereof, and an exhaustport. 23 atthetop. Y L f Operative in the cylinder 21 are piston valves 24 and 25, the latter being connected through a wrist lpin 26 with the eccentric rod 8, and the two 'being connected rigidly together through yokes 2 7r and 28, see Fig. 2,

attached respectively to the pistons 24 and with bearings 2 and 3 for a crank shaft "4.

25, and connected together by tie rods 29, 29 vwhich pass slidably through the upper portion of the'cylinder casting v9and the top of Y tlie'crank case 1. In, the cylinder 21 and interinediate the pistons 24fand 25, provision is made for a spark plug 30 orf other device for igniting 'explosive gases in .the cylinder.

Asrshown in Fig. lg'tlie piston 25 is for-med with a passage 31 through which conimuni fao shown the entire upper portions ofthe 'cyl4 ndels 10-11 and; 2l .Surrounded by a Wafer.v

jacket 32, the'co'oling system may be varied, as may be found necessary or desirable','with out departingl fromV the invention.

The piston valves 24 and' 25-,like'the piston- 12, are provided with suitable packingrings and order 'to preventwthe'se packing ringsY from" catching lupon the edges of the y ports 15,- ie and 175th@ iaaersie provided with bridges'eiitending longitudinally of the cylinders, onel ofithcse bridgesY 34 inthe port 1'51being illustrated lin Fig. In-this case, the'brid'g'e isniade'hollow tov provide a coni nesting p'assagefg35 between-adjacent ends ot th'eI-waterjacket; f i A' i Assumiiigthe-various parts are in the positioi'is illustrated inthe drawings and tlie'shalt (4) turningr inthe direction ofthe arrowin Fig. 2, thepiston 12'has". recently passed the topA of its stroke'. A charge has just been exploded in the combustion chamber or 'cylf inder 21, and it bwilljbe` noted that the port? 17 is shu't'poitby the*vali/c25V from the combustioir chamber', and tha'tithle port 15 is partially open sofas 'toi permihthe products of combustion to2 eiipaiid into ,the cylinder 10-11 above'the piston12'. The `piston 24 also shutso'ii thel port lfro-in the exhaust port 23 yand port 1G iis'T closed. v I

As lthe piston 12 moves downwardly, the piston valvesf24" and 25 move upwardly, therebyfurthe'r opening both the .port 15 and the port 17 and permittingl `a fresh charge or combustible gases to be' drawn through the port'22, the .passage31, and the port v17 into the'lowerlargersectionfot 'the cylinder 1 0-.11'. Continued downwardlnioi'fement of the piston 12 'eventually uncovers the port 16 and permits the'escape ot theV products of'com bustio'n'dromthe:y lesser' portion 10 of the cylinder 10-1'1, the pressure within the upper partv ot the said 'cylinder' 10-11 and the combustion chamber 21 dropping-nearly to thatv 01' the atmosphere. 12 reaches thelowe'rcnd of its stroke, the pisYN ton Valves 24 and 25 reverse their movement, andas the piston 12 passes the'bottom of its stroke but before it has risen 'far enough to close the port16, the valveelement 24 cuts oif the port', 15 4from the combustion cham,- ber, andverylshortly tlierea'fteropens said port`v to the exhaust' 23. The' piston 12 then closesthe port 16, and for the ,qreateiportion of itsupward 'stroke forces the products of combustion remaining" inthe cylinderoutthrough the portl and the exhaust port 23.A

.,Avsvpreviously stated, a fresh charge o'f combustible gases is drawn into thezlower enlarge-d section of the cylinder 10-'11 Before the piston.

isasas through the downward movementotthe piston 13, and when the piston reaches the bottoin of its stroke, the annular space in the said enlarged. portion 11 oi' the cylinder has reached its greatest volume and is practically fulloffuel. As the piston starts to move upward, the valvejelem'ent 25 which is moving downwardly, as i previously "described, shuts f oi'fgthejport117from the port 22, and almost immediately thereafter opens the port 17 iiito'th'e'cyliiider'21in` the space between the pistions 24and 2,5, which space constitutes the combustion chamber, and which, asfpreviousl-y described, has been'clbsedo'iifrointhe port 15,. Under these circumstances, the cen'-v tinued upward i movement of i they piston 13 compresses the gases in pistons 24 and 25.v

lvVh'enthe piston has -nearlyreached-l the top oiits stroke, ther'portl is'- closed to the exhaust bythe upward'mov'ement'et thef valve elemeiit24, and during the rest of the 'stroke the remaining products of combustion in the cylinder are campi-esseci to a pressure approximatingl that ofthe compression Vpressure in the combustionr chaiiiber Within' afi-short the 'space between the interval atthe tepel' the pistons'troke, the

sults are obtained, among-` which may be' noted the comparatively small iiiii'iiber otparts,4 the 'comparatii'iely Vsmall space occupied, and theV low expense of manufacture due! tog'the use ofonly one cylinder, onev piston, one connectlll-5 ing rod, and one crankto performthe' service heretoforerequiring two' of eaohfof'the'se Y parts. Vith this construction, also, there is a considerable gain in elhcien'cy'v achievediby reduction to a minimum'or friction andof `heat losses and by improvement oit volu-` metric eiiiciency owing tothe actfthatf the.

combustion chamber is cutoii roiiifthefin# taking' portionllof'the-cylinder whereb'yf the'v new charge cannot be 'reducedbyre-eipaiil si'on ofl old products ofcnibusti'on remaiir ing` in the combustion chamber. l

A furtherimportant gain in' eeeny' is obtained by' proportining 'the cylinder and pistonV as described so that'tlie 'volume'of the annular space swept o'u'tby'the lower portion of the piston issmall'er Vthan thejvo'lume displacedby theupper portion of said piston.

In this manner, the products ofcombustionV i' areeXpanded to avlume' zgreater than that of the original charge, the pressure .at release lill being` therebyredueed Yahd workfbeiirg rderived from expansion' which ,would otherwise be lost into the exhaust. Obviously, it mayV be desirable, under some circumstances, as where lightness inv weiglit'is an essential, to have the eii'ective area of the upper portion of the piston smaller than the effective area of the lowerportion, although this 4reducesthe efciencyas indicated above.

Again it isabsolutely impossible lwith the construction shown for backire to occur, since the intake passage 22 is atno time in direct communication with the combustion chamber.

Obviously the engine is subject to some modilication without departure `from. the essential features of the invention.

I claim:

1. The combination in an internal combustion engine, of a power cylinder having two portions of different diameters; a piston in' said cylinder having two diameters to fit the two portions oit' saidcyliiider; a valve cylinder; a port opening from said valve cylinder into the larger portion of the power cylinder; a second port openingl from said valve cylinder into the smaller portion of said power cylinder; means for controlling said ports; and a port opening from the power cylinder controlled by the piston.

2. The combination in an internal combustion enOine of a Gower c linder havin@ twov portionsvof dierent diameters; a piston in said cylinder; a valve cylinder ;'a combustion chamber in said valve cylinder; means for connecting said combustion vchamber alternately to the two portions of said working cylinder; and a port opening from the power cylinder controlled by the piston.

3. VThe combination in an internal combustion engine, of a cylinder; apiston in said cylinder; a power space in said cylinder vclosed in by the head portion of said piston; an annular compression space closed in by' an enlargement on the skirt oi' said piston; a combustion chamber; an opening between said combustion chamber and said power space; a valve element for controlling said opening; a second opening between said combustion chamber' and said compression space; a valve element for controlling said second opening; and a port opening from the power cylinder controlled by the piston.

fl. The combination in an internal combustion engine, of a'power cylinder having two portions of different diameters; a piston in said cylinder having two diameters tor iit the two portions of said cylinder; a combustion chamber; a port opening from said combustion chamber into the larger` portion of the power cylinder; a second port opening from said combustion chamber into the smaller portion of said power cylinder; means for controlling said ports; and a port opening from the power cylinder controlled by the piston. y

5. The combination in an internal combustion engine, of a cylinder having power and compression sections; a pistony operative in both of said sections and having a'.l greater effective area in the power than in the compression section; a combustion chamber; a port b etweeiithe combustion chamber and` the power space; a second portbetween the combustion chamber and the compression space; and valve means controlling said ports.

v 6. The combination in aninternal combustion engine, of a cylinder havingpower vand'Y space; and valve means controlling said ports,

7. The combination in an internal combustion engine, of a power cylinder; a piston i in said cylinder; anexhaust port controlledV by said piston; a second exhaust port in said cylinder supplementing the piston controlled port; valve mechanism for controlling said second exhaust port; la combustion chamber external to said cylinder; and valve mechanism for establishing and severing communication between said cylinder and combustion chamber.

8. The combination of-a power cylinder; a piston'iii said cylinder; an exhaust port controlled by said piston and a secondary and .supplemental exhaust; a second port in said cylinder; a combustion chamber; and valve mechanism arranged to establish and sever communication from said port alternately to the combustion chamber and to the secondary exhaust. 4

9. The combination, in an internal com bustion engine, of a power cylinder having two portions of different diameters, a piston in said'cylinder enclosing therein two chainbers, a valve cylinder adjacent said power cylinder, la port connecting saidv valve cylinder with one of said chambers, a second port `.connecting said valve cylinder with the other chamber, two yvalves in said valve cylinder controlling said ports, and means external to the valve cylinder for rigidly connecting saidy valves. f l

10. The combination, in an internal coinbustion engine, of acylindei',a piston in said cylinder, a power space in said cylinder closed in by the head .portion of said piston, an annular compression space closed in by an Venlargement on the skirt of said piston, a

valve cylinder, a port between` said valve cylinder and said power vspace, a valve elementV in said valve cylinder for controlling said port, a second port between said valve cylinder and said compression space, a second valve element in said valve cylinder for controlling said second port, and means external to the valve cylinder for rigidly connecting said valve elements. 1

l1. The combination, in an internal comlili 

